Display devices



gauge Alig- 12, 1958 N. vlszLocKY ETAL DISPLAY DEVICES SPIDER FIGQBINVENTORS NICHOLAS VISZLOCKY STEVEN VlSZLOCKY ATTORNEY Lamu Unit/eidStates Patent O ice 2,846,799

DISPLAY DEVICES Nicholas Viszlocky and Steven Viszlocky, New York, N. Y.

Application September 18, 1953, Serial No. 381,018

3 lClaims. (Cl. 40-130) This invention relates to display devicesutilizing polarized light and its effects; more particularly it relatesto devices of such type wherein changeable images and colors are visibleto the observer.

An object of the invention is to provide an improved display device ofthis character wherein it will be possible for an observer to see noveldecorative color changes caused by changing polarized light played uponv a birefringent material.

A further object of the invention is to provide a display device of thischaracter capable of producing the optical effects ordinarily attainedby multiple bulbs set in complex circuits with liashers.

Still a further object of this invention is to provide improved imagesfor display devices of this character.

To the accomplishment of the foregoing and such other objects as mayhereinafter appear, this invention consists in the novel constructionand arrangement of parts hereinafter to be described in detail and thensought to be defined in the appended claims, reference being had to theaccompanying drawings forming a part hereof which show, merely for thepurposes of illustration, preferred embodiments of the invention, itbeing expressly understood, however, that changes may be made inpractice within the scope of the claims without digressing from theinventive concepts.

In the drawings in which similar reference characters denotecorresponding parts:

Figure 1 is a vertical section of a display device constructed accordingto the principles of this invention.

Figure 2 is a perspective view of one form of image and image supportillustrating the details of its constructron.

Figure 3 is a plan view of another form of image and image support.

Figure 4 is an enlarged view showing a portion of the image illustratedin Figure 3.

Referring to the drawing, the display device has an opaque housing 12surrounding and supporting the other component elements. For purposes ofclarity, the brackets or other conventional means used for supportingpurposes are omitted. Also omitted are means by which display device 10may be hung from a wall or held in place on a shelf. The hollow interiorof housing 12 is preferably circular. Attached to the sides of housing12 by a bracket through posts 19 is a base compartment 13 which containsthe electrical control elements for display device 10. Thus insidecompartment 13 is a motor 14 whose shaft 16 extends through into housing12. For ready access to the motor and other electrical elements, the endplate 15 may be removably attached to compartment 13. The startingbutton 17, motor switches, etc. can project out from end plate 15.

Attached to motor shaft 16 are a plurality of spider legs 18 whichextend centrally past uorescent light 20 and the bracket to atranslucent isotropic sheet 22. The spider legs 18 which attach totranslucent sheet 22 at ...are v- Patented Aug. 12, 1958 sheet in placeand make it rotatable. Co-extensive with translucent sheet 22 is a sheet24 of light polarizing material such as Polaroid which has a fixedpolarizing axis. The sheets 22 and 24 which may be united or laminatedtogether in any suitable way, rotate as a unit when spider legs 18 areturned by motor 14 through shaft 16.

The light source, consisting of a toroidal fluorescent light 20 such asthe Circline light or a tubular light of the neon type arranged in acoil, is supported inside housing 12 in any manner which leaves itscentral opening an unencumbered passage for the spider legs 18. Forexample, thelight can be clamped to the same bracket which supportscompartment 13. The electrical connections for fluorescent light 20 leadout of compartment 13, with transformer 21 and starter button 17 for thelight being housed inside compartment 13. As a constructionalcharacteristic of display device 10, compartment 13 is smaller than thecentral opening of light 20 so that the light bulb may be inserted andremoved without disturbing compartment 13 and its contents. The annularbase 23 is removably bolted' or screwed to the rest of housing 12 toprovide ready access to light 20 for its maintenance or replacement.

A particular advantage of the toroidal or tubular light (both of whichare hereinafter called circular) lies in the large surface area foremission of high intensity light. A less preferred alternative lightsource comprises linear uorescent lights situated along the sides ofhousing 12 so as to leave an unencumbered central passage. Of course,lights so situated may be used in addition to the circular one, butordinarily a single circular fluorescent light will provide sufficientillumination for display device 10. As a further advantage of thecircular light source, placement of the light along a locus about midwaybetween the center and the outer periphery of translucent sheet 22facilitates uniform diffusion of light through the translucent sheet topolarizer 24 so that an observer looking at light 20 solely throughsupcrposed sheets 22, 24 would see a substantially uniform field of highintensity light issuing from sheet 24. In this connection there is someadvantage to coating the interior surface portion of housing 12 lyingbehind light 20 with a light reflecting material.

Since the polarizing sheet 24 has a fixed polarizing axis, when motor 14is energized to rotate its associated shaft 16 and spider legs 18thereby rotating sheet 22, 24 in its plane before circular light 20, asviewed from open end of housing 12 the plane of polarization of thelight passing through sheets 22, 24 is constantly changing direction.

At the open or viewing end of housing 12 a stationary analyzer sheet 26of light polarizing material such as Polaroid is provided. This analyzersheet 26 has a fixed polarizing axis and has substantially the samedimension as sheets 22, 24. An observer viewing the polarized lightpassing directly from rotating polarizer 24 to analyzer 26 wouldcyclicly sce the variations in light intensity so characteristic ofcrossing and uncrossing polarizers. The light would periodically go fromminimum to maximum intensity. Interposition of an image 28 fashionedfrom a birefringent material such as regenerated cellulose or cellophanealters this pattern by its anisotropic effect. rl'he cyclic change inlight intensity is transformed into a cyclic change in the color patternof the image. These color changes are coupled with the aforementionedvariation in actual light intensity, but this variation is ordinarilynoted by the eye of an observer as phases of dull and bright colors.

A backing 30 may be placed behind image 28 for providing sufficientrigidity to make it self-supporting, and if image 28 is cellophane,backing 30 adds a desirable degree of fire resistance. Backing 30, whichis of a suitable isotropic material may be joined to the birefringentimage in any suitable manner, e. g. by an isotropic adhesive. In apreferred form of the invention both image 28 and backing 36 arerecessed into an isotropic image support 32. As shown in Figure 2,stamped out cellophane image R may be simply dropped into a matchingslot in image support 32 and a closely fitted backing piece (not shown)placed in the slot to sandwich the image between backing 30 and support32. Cement may be applied to the lateral edge of backing 30 and/or thesides of the image slot in support 32. This construction provides asimple method of securing an increased image from thin segments ofbirelringent material. Generally support 32 and backing 30 will be ofthe same isotropic substance, but colorful effects may be obtained ifone of them, preferably backing 30, is tinted. The optical effect causedby the edges of backing 30 and the slot in support 32 is small and maybe further decreased by placing the assembled image in housing 12 withsupport 32 facing the viewing end as shown in Figure l.

The details of a type of image 28 productive of unusual optieal effectsare shown in Figures 3 and 4. The image support 132 is an opaque or anisotropic translucent sheet having a set of perforations or apertureswhich form a desired pattern such as the numeral 8 of Figure 3.Underlying each aperture is a birefringent segment. Each segment mayconsist of one or more layers of birefringent material. Differentoptical effects are obtained according to the selection and orientationof the segments. Thus, as shown in Figure 4, the segments underlyingapertures 34, 36, 38, 40, 42, 44 may be individually oriented with theirsignificant axis or direction as shown by the arrows to an overallrandom pattern of orientation. Since each segment has its individualeffect on the polarized light passing through its aperture as the planeof polarization changes with the rotation of polarizing sheet 24,individual apertures will grow brighter or darker as well as change incolor. Since a random pattern of orientation was preselected, the imageas a whole, i. e. the numeral 8, will appear to twinkle or pulsate invarying colors. Since the segments may be initially of different colortints as well as oriented in different directions, there is a tremendousamount of variation permissible within this single pulsating ortwinkling effect.

By appropriate design of the pattern apertured in image support 132 andproper selection andorientation of the birefringent segments in eachaperture, thereY may be attained many of the effects commonly secured bydisplays made of individual bulbs set in timed sequence. Thus byorienting the segments sequentially with, for example, a progressive 5or 10 angular increase from a starting segment to its next adjacentsegment on through all the segments, rotating the polarizer will causethe colors to travel or run around the numeral 8. With a double row ofapertures as shown in Figure 3, the colors may go in one directionaround one row and in the opposite direction around the other row. Thistravelling or running effect can be made more striking by havingcellophane segments of one tint, e. g. pink in one row of apertures anda different tint, e. g. blue in the other row of apertures. Similarlyother effects like that of expanding and contracting, ag-waving,revolving wheel, pyrotechnic, sunray, smoke and steam, may be obtainedby such simple expedients as forming the appropriate designs with theapertures and selecting proper orientation for the birefringentsegments.

Unique combination effects may be attained. For example the revolvingwheel effect may be obtained by cyclicly blanking out sections of theimage. Thus by positioning spaced apart pie shaped opaque sectors (notshown) just adjacent backing 30 and rotating them through suitableconnection with motor 14 at the same or at a different rate thanpolarizing sheet 24 rotates, the sectors will cyclicly black outsufficient apertures to give the optical effect of revolving wheelspokes. Then if the apertures were of different tints randomly oriented,the revolving wheel would appear to pulsate or twinkle n many varyingcolors.

In operation of a display device having the apertured form of imageillustrated by Figures 3 and 4, it is important to relate the rate ofcolor change to the optical effect desired. Thus for the pulsatingeffect motor shaft 16 should rotate at a relatively rapid rate, e. g. 60revolutions per minute. Generally speaking,V a minimum rate of.' 20revolutions per minute is contemplated for all the effects attainablewith the apertured image. This is in contrast to the form illustrated inFigure 2 for which 4 or 5 revolutions per minuteis satisfactory.

It is to be understood therefore that an infinite number of combinationsof color flow and change of color in images of all conceivable shapesmay be secured by suitably positioning birefringent materials inapproximately apertured image supports like 132. The examples hereingiven of color flow and design combinations are illustrative only, andare in no sense to be regarded as limitations. Also, variation in thestructural details are possible and are contemplated within the scope ofthe claims. There is no intention of limitation to the exact detailsshown and described.

What is claimed is:

l. An illustrated display device comprising: a housing: a motorcompartment centrally located at the base of said housing; a motor inthe compartment; a shaft rotatable by said motor extending from thecompartment interiorly of said housing; a set of spider legs positionedon said shaft; a translucent light diffusing sheet rotatably supportedadjacent the peripheral edge thereof by said spider legs; a circularfluorescent light spaced radially outward of said spider legs, thecentral opening of the circular uorescent light being wider than themotor compartment whereby said light may pass around said compartmentupon removal through the base of the housing, said light being generallypositioned to substantially uniformly illuminate the translucentdiffusing sheet; a light polarizing sheet coextensive with saiddiffusing sheet and attached thereto for rotation therewith; astationary birefringent image supported in said housing; and astationary light polarizing sheet supported in said housing; saidrotatable diffusing and polarizing sheets, said stationary birefringentimage and said stationary polarizing sheet being in that order alignedin said housing between said light source and the eye of an observerwhereby as said motor and spider legs turn said rotatable polarizingsheet the observer views variable color effects.

2. The apparatus of claim 1 wherein said image is disposed in a slottedimage support and held there sandwiched between said image support andan isotropic backing, the surface of which matches that of said slottedimage support.

3. The apparatus of claim 1 wherein said image comprises an imagesupport having a design formed thereon by a plurality of apertures; andwherein each individual aperture has therein an individually orientedimage segment of birefringent material whereby turning of said rotatablepolarizing sheet individually effects a change in the color andintensity of the light passing through each aperture.

References Cited in the file of this patent UNITED STATES PATENTS2,146,962 Land Feb. 14, 1939 2,261,957 Burehell Nov. ll, 1941 2,313,831Martin Mar. 16. 1943

